The following data set examines the environmental protection attitudes between rural and urban residents. How do you calculate the estimated pooled population variance from the data below? RURAL X M (X M)2 URBAN X M (X M)2 8 2.75 7.56 14 6.67 44.44 3 7.75 60.06 2 5.33 28.44 14 3.25 10.56 6 1.33 1.78 18 7.25 52.56 mean 1 10.75 mean 2 7.33 0 0.00 SS 130.75 SS 74.67 df 3 df 2 S2 43.58 S2 37.33 (3/5) (43.58) + (2/5) (37.33) (3/6) (45.38) + (2/6) (37.33) (3/5) (10.75) + (2/5) (7.33) (3/6) (10.75) + (2/5) (7.33)